Many transmitters are constructed in a manner that results in a known type of distortion appearing in the signals that are output. For example, many transmitters can be characterized by the presence of deterministic distortion in the phase of the signals that are output. Periodic distortion is one type of deterministic distortion caused by a Periodically Distorted Unit Interval (PDUI). With deterministic distortion caused by a PDUI, each edge of the signal is always affected by a phase error that can be defined by a discrete function phase(k), where “k” is the edge number of the signal. A signal affected by a PDUI has a periodic phase(k). The size of the period can be one or more unit intervals (UIs).
Available clock and data recovery (CDR) systems are able to account for some types of distortion, but remain largely intolerant to others. For example, conventional CDR systems are often able to correct for non-deterministic distortion, e.g., jitter, but are not optimized to correct for deterministic distortion.